Repotting guide

When & how to repot Creeping Willow (Salix repens)

Also called Creeping willow, Creeping sallow.

More about creeping willow

About Creeping Willow

Salix repens · also called Creeping willow, Creeping sallow · flowering

Salix repens is a low, spreading deciduous shrub native to damp heathlands, dune slacks, and fens across Europe including Britain and Ireland. It thrives in full sun with consistently moist soil, making it an excellent choice for bog gardens, rain gardens, or stabilising sandy coastal banks. The most critical care point is adequate moisture — even brief drought will cause leaf scorch and dieback. Salix species contain salicylates and are considered mildly toxic to cats and dogs.

Mature size: Up to 1 m tall and 1.5–2 m wide, though the var. argentea form can be slightly more compact.

Watch for — Honey fungus (Armillaria spp.): Willows are notably susceptible to honey fungus, which causes sudden wilting and death of shoots; look for white mycelial fans under bark at the base. There is no chemical control — remove and destroy affected root material.

How to tell creeping willow needs repotting

Repotting on a calendar is less reliable than reading the plant. For creeping willow, watch for these signs:

Roots spiralling thickly out of the drainage holes or pushing the whole plant up out of the pot.
The pot is so packed that water runs straight through in seconds and barely wets the soil.
It has split a plastic pot, or the rootball is a solid mass with almost no soil left when you slide it out.
Growth and (for creeping willow) flowering have clearly stalled despite good light and feeding — but remember this plant likes being snug, so a little crowding alone is not a reason to repot.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot creeping willow

Only every 2–4 years, when genuinely crowded. Creeping Willow is one of the plants that genuinely prefers a snug pot — it grows and flowers better with its roots a little restricted, so resist the urge to repot it on schedule. Low, mat-forming to mound-shaped deciduous shrub with slender, spreading or ascending stems; spreads by both stems rooting where they touch the ground and by suckering..

What size pot to step creeping willow up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Creeping Willow positively prefers a snug pot: it flowers and grows better when the roots are a little restricted. The single biggest repotting mistake here is over-potting — dropping creeping willow into a pot two or three sizes up. All that surplus soil holds water the small root system cannot use, stays cold and wet, and rots the roots within weeks. When in doubt, choose the smaller pot.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot creeping willow

Early spring, just as new growth restarts, is the ideal window for creeping willow. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting creeping willow

Confirm it actually needs it. Slide creeping willow out and check the roots. Only continue if it is genuinely packed — this plant prefers a snug pot, so if there is still soil and room, put it straight back.
Pick a pot only one size up. Choose a pot just 2–3 cm wider with good drainage. Resist anything bigger; over-potting is the main killer here.
Ease it out gently. Water lightly the day before, then tip creeping willow out, supporting the base. Tease the outer roots free only enough to stop them circling.
Repot at the same depth. Add a layer of fresh moist to wet, sandy or loamy, neutral to mildly acid, set the plant so the soil line sits exactly where it did before, and backfill around the sides, firming lightly.
Settle it in. Water once to settle the soil, then let it sit. Hold off on more water until the top of the soil dries — fresh soil around a small root system stays wet for a while.

Aftercare

Because the new soil holds more water than the old crammed rootball did, ease right back on watering — let the top of the soil dry before you water creeping willow again, or you will rot the roots in the very pot you just moved it to. Keep it out of harsh direct sun for a fortnight. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for creeping willow

Creeping Willow wants moist to wet, sandy or loamy, neutral to mildly acid. Tolerates a range of soil textures including heavy clay and light sand, provided moisture is consistent; avoid shallow chalk soils which cause chlorosis. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting creeping willow — frequently asked questions

How often should you repot creeping willow?

Only every 2–4 years, when genuinely crowded for creeping willow. Only repot creeping willow every 2–4 years, and only when it is genuinely root-bound — it flowers and grows best slightly crowded. Step up just one pot size in spring using moist to wet, sandy or loamy, neutral to mildly acid. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does creeping willow need?

When is the best time of year to repot creeping willow?

Does creeping willow like to be root-bound?

Yes — creeping willow genuinely flowers and grows best when slightly pot-bound, so do not rush to repot it. The mistake to avoid is over-potting into a much larger pot: the excess soil stays wet, the roots cannot use it, and the plant rots. Only repot every few years and only one snug size up.

Should you fertilise creeping willow after repotting?

Not immediately. Wait about 4 weeks after repotting creeping willow. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.